logd: improve details on chatty records
- Report applications UID, TID/PID by name.
- change wording to have an accurate connotation
- drop privilege check since filtered upstream
Bug: 19608965
Bug: 20334069
Bug: 20370119
Change-Id: I2b1c26580b4c2de293874214ff5ae745546f3cca
diff --git a/logd/LogBufferElement.cpp b/logd/LogBufferElement.cpp
index a173e63..6a05700 100644
--- a/logd/LogBufferElement.cpp
+++ b/logd/LogBufferElement.cpp
@@ -14,7 +14,9 @@
* limitations under the License.
*/
+#include <ctype.h>
#include <endian.h>
+#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
@@ -48,19 +50,89 @@
delete [] mMsg;
}
-// assumption: mMsg == NULL
-size_t LogBufferElement::populateDroppedMessage(char *&buffer, bool privileged) {
- static const char format_uid[] = "uid=%u dropped=%u";
- static const size_t unprivileged_offset = 7;
- static const char tag[] = "logd";
-
- size_t len;
- if (privileged) {
- len = snprintf(NULL, 0, format_uid, mUid, mDropped);
- } else {
- len = snprintf(NULL, 0, format_uid + unprivileged_offset, mDropped);
+// caller must own and free character string
+static char *tidToName(pid_t tid) {
+ char *retval = NULL;
+ char buffer[256];
+ snprintf(buffer, sizeof(buffer), "/proc/%u/comm", tid);
+ int fd = open(buffer, O_RDONLY);
+ if (fd >= 0) {
+ ssize_t ret = read(fd, buffer, sizeof(buffer));
+ if (ret >= (ssize_t)sizeof(buffer)) {
+ ret = sizeof(buffer) - 1;
+ }
+ while ((ret > 0) && isspace(buffer[ret - 1])) {
+ --ret;
+ }
+ if (ret > 0) {
+ buffer[ret] = '\0';
+ retval = strdup(buffer);
+ }
+ close(fd);
}
+ // if nothing for comm, check out cmdline
+ char *name = android::pidToName(tid);
+ if (!retval) {
+ retval = name;
+ name = NULL;
+ }
+
+ // check if comm is truncated, see if cmdline has full representation
+ if (name) {
+ // impossible for retval to be NULL if name not NULL
+ size_t retval_len = strlen(retval);
+ size_t name_len = strlen(name);
+ // KISS: ToDo: Only checks prefix truncated, not suffix, or both
+ if ((retval_len < name_len) && !strcmp(retval, name + name_len - retval_len)) {
+ free(retval);
+ retval = name;
+ } else {
+ free(name);
+ }
+ }
+ return retval;
+}
+
+// assumption: mMsg == NULL
+size_t LogBufferElement::populateDroppedMessage(char *&buffer,
+ LogBuffer *parent) {
+ static const char tag[] = "logd";
+ static const char format_uid[] = "uid=%u%s too chatty%s, expire %u line%s";
+
+ char *name = parent->uidToName(mUid);
+ char *commName = tidToName(mTid);
+ if (!commName && (mTid != mPid)) {
+ commName = tidToName(mPid);
+ }
+ if (!commName) {
+ commName = parent->pidToName(mPid);
+ }
+ if (name && commName && !strcmp(name, commName)) {
+ free(commName);
+ commName = NULL;
+ }
+ if (name) {
+ char *p = NULL;
+ asprintf(&p, "(%s)", name);
+ if (p) {
+ free(name);
+ name = p;
+ }
+ }
+ if (commName) {
+ char *p = NULL;
+ asprintf(&p, " comm=%s", commName);
+ if (p) {
+ free(commName);
+ commName = p;
+ }
+ }
+ // identical to below to calculate the buffer size required
+ size_t len = snprintf(NULL, 0, format_uid, mUid, name ? name : "",
+ commName ? commName : "",
+ mDropped, (mDropped > 1) ? "s" : "");
+
size_t hdrLen;
if (mLogId == LOG_ID_EVENTS) {
hdrLen = sizeof(android_log_event_string_t);
@@ -70,6 +142,8 @@
buffer = static_cast<char *>(calloc(1, hdrLen + len + 1));
if (!buffer) {
+ free(name);
+ free(commName);
return 0;
}
@@ -86,16 +160,16 @@
strcpy(buffer + 1, tag);
}
- if (privileged) {
- snprintf(buffer + hdrLen, len + 1, format_uid, mUid, mDropped);
- } else {
- snprintf(buffer + hdrLen, len + 1, format_uid + unprivileged_offset, mDropped);
- }
+ snprintf(buffer + hdrLen, len + 1, format_uid, mUid, name ? name : "",
+ commName ? commName : "",
+ mDropped, (mDropped > 1) ? "s" : "");
+ free(name);
+ free(commName);
return retval;
}
-uint64_t LogBufferElement::flushTo(SocketClient *reader) {
+uint64_t LogBufferElement::flushTo(SocketClient *reader, LogBuffer *parent) {
struct logger_entry_v3 entry;
memset(&entry, 0, sizeof(struct logger_entry_v3));
@@ -114,7 +188,7 @@
char *buffer = NULL;
if (!mMsg) {
- entry.len = populateDroppedMessage(buffer, clientHasLogCredentials(reader));
+ entry.len = populateDroppedMessage(buffer, parent);
if (!entry.len) {
return mSequence;
}